A tire mounting apparatus and method of the above mentioned general type are known from the company catalog “Balancing and Diagnostic Systems”, 2002 Catalog RA 1020e of the company Schenck RoTec GmbH, of Landwehrstrasse 55, D-64293 Darmstadt, Germany. At pages 116 and 117, the English version of the mentioned catalog discloses a tire mounting or assembly machine for vehicle wheels, whereby the tire is at first laid sloping obliquely onto the wheel rim of a vehicle wheel to begin the tire mounting process. The lower tire bead of the tire is partly located within the recessed deep well of the rim, and partly protrudes outwardly above the upper rim flange. To carry out the tire mounting process, the wheel rim is supported and tightly held or clamped, and the tire mounting head (also called a draw-down head or pull-on head) is lowered until the bead deflector and the press-in or press-down roller contact the side of the tire. Then the mounting head is rotated about the rim axis. The bead deflector pushes against and along the tire bead to ensure that the tire bead lies radially outwardly relative to the rim flange, and then the following press-in roller axially presses the tire bead downwardly into the deep recessed well of the wheel rim, while simultaneously the lower tire bead is pressed into contact against the lower rim flange. The mounting of the two tire beads onto the rim can be carried out, as desired, either together in common in one operation, or sequentially in two rotations of the mounting head. The mounting head is adjustable to various different wheel rim types, e.g. different rim diameters, rim widths, or rim profiles or shapes. The adjustment can be achieved automatically in connection with a preceding rim type recognition.
In practice, it has been found that the rim type recognition can give incorrect rim type identifying data, for example due to a malfunction or various type-recognition errors. Errors can also arise due to interference in the transmission of the type identifying data from the type recognition arrangement to the tire mounting apparatus. Still further errors can arise during the automatic or manual adjustment of the bead deflector and/or the press-in roller, as well as the drive movements of the mounting head. If the wheel rim is clamped on the rim support in an uncentered or tilted manner, it gives rise to further positioning errors.
The above mentioned errors can cause an improper working position of the bead defector and/or the press-in roller relative to the particular wheel rim being processed. In a worst case situation, such improper working position can cause the bead deflector to collide with, gouge into, or scrape along the wheel rim flange, or excessively deflect the tire bead, and thereby damage the wheel rim and/or the tire. Since the contact of the bead deflector with the wheel rim flange occurs on the visible decorative side of wheel rim, even the slightest visible damage leads to rejection of the wheel rim, or damage of the tire leads to rejection of the mounted tire-rim combination, in subsequent quality control. Furthermore, any damage to the rim flange or the tire bead can make it impossible to properly and successfully mount the tire on the rim. The equipment itself, e.g. the bead deflector, can also become damaged by improperly contacting and pressing against the rim flange.